Heat transfer device



July 19, 1966 Filed Nov. 20, 1963 FIG. 1

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I m a d t m N N g INVENTORS JAMES ANDERSON BY 'CARL A. KLOBASSA ATTOR NEYS July 19, 1966 J ANDERSON T 3,262,020

HEAT TRANSFER DEVICE 2 Sheets-Sheet 2 Filed Nov. 20, 1963 FIG. 3

TRANSMITTER INVENTORS JAMES ANDERSON CARL A. KLOBASSA WM M ATTORNEYSUnited States Patent 3,262,020 HEAT TRANSFER DEVICE James Anderson andCarl Arsen Klobassa, Dallas, Tex., assignors to Continental ElectronicsManufacturing Company, Dallas, Tex., a corporation of Texas Filed Nov.20, 1963, Ser. No. 324,954 6 Claims. (Cl. 317-100) The present inventionrelates to a heat transfer device, and, in particular, to apparatus forcooling aradio frequency load utilized in the test operation of radiotransmitters.

When dummy loads are employed to test radio transmitters, it isessential to provide an adequate means for dissipating heat generated bythe passage of current through the load. Various means have beenutilized in the past to dissipate such heat, including liquid cooled devices, however, the prior art has not provided sufliciently rapid andeflicient heat transfer.

Accordingly, it is an object of the present invention to provide animproved heat dissipating system.

It is another object of the present invention to provide an improvedsystem for moving cooling fluid past a heater element.

. It is still another object of this invention to provide a system fordissipating heat generated by the passage of current through resistiveelements in a load.

A dummy load for testing radio transmitters may include a plurality ofresistive elements connected in series. According to the invention, theelements are vertically arranged within glass tubes supplied with liquidfor cooling purposes. Vents at the top of the tubes provide for theescape of vapor produced by the heated resistors. Within the tubes, andenclosing the resistors, are suitably mounted sleeves connected to allowfluid to pass through the space between the resistors and the interiorwalls of the sleeves. The steam produced by the heated resistors withinthe sleeves induces a siphon elfect which pulls the water upwardlythrough the passages between the resistors and sleeves in a rapidmanner, thus providing a high rate of heat transfer to quickly andefliciently cool the load. Other objects of the invention will beapparent from the following detailed description with reference to theaccompanying drawings, which, by way of illustration, show a preferredembodiment of the invention and what is now considered to be the bestmode of applying the principles thereof.

In the drawings:

FIG. 1 is a perspective view of a transmitter dummy load and the heatdissipating system of this invention;

FIG. 2 is a sectional view of a resistor and heat transfer unit;

FIG. 3 is a sectional view taken along line 33 of FIG. 2; and

FIG. 4 is a schematic showing the electrical circuit for FIG. 1.

Referring in detail to the drawings, wherein similar reference numeralsidentify corresponding parts throughout the several views, a transmitter12 is electrically connected to the ends 14 and 16 of a series connecteddummy load line 19 (see FIGS. 1 and 4). The load line includespluralities of resistors 20 and 22 connected in series by a balanced twowire transmission line 18. The resistors may be tapered in resistancevalue to obtain equal amounts of power dissipation in each pair.

A plurality of cylindrical, vertically disposed glass tubes 24 enclosethe portions of dummy load line 19 which include the series connected,cylindrically shaped resistors 20 and 22. Tubes 24 may be made of acommercially available glass sold under the trade name Pyrex. Ends 14and 16 of transmission line 18 pass into lower extenice sions 26extending transversely near the bottom of the first pair of tubes 24through water tight plugs 28. The bottom of each tube 24 is connectedthrough water supply conduit 32 (FIG. 1) to a main water supply tank 34.The water level in the tank is high relative to tubes 24 to provide agravity feed, and a valve 36 enables an individual to control the amountof water entering tubes 24. The resistors 20 are centered withinrespective vertical tubes 24 at approximately the mid portions thereof(see FIGS. 2 and 3). A glass sleeve 38 is mounted concentrically aboutresistor 20. Sleeve 38 is held in place by three tabs 40 at both thebottom and top of the sleeve. The tabs may be made of a commerciallyavailable plastic sold under the trade name Teflon and are secured toresistor 20 by screws 42 and co-operating nuts 44. Six strap connectors46 at both the top and bottom of resistor 20 provide electrical andmechanical connections between the resistor and a pair of elbowconnectors 48. Connectors 46 are secured to the resistor and elbowconnectors by screws 50 and nuts 52. Elbow connectors 48 include acylinder 54 press fit to flanged disc 56, which, in turn, is secured toa plug element 58 by a screw 60. An elbow 62, into which plug 58 ispressed, is frictionally secured to transmission line 18 to complete thelink.

Thus, an electrical and mechanical connection is provided between thesections of transmission line 18 and the connecting resistors 20. Thetransmission line provides :the connection between each vertical tube,passing through water tight plugs 28 in lower extensions 26 and upperextensions 29. A bus connector 64, connected to the ends of each of thetwo parallel lines of vertical tubes 24, provides an electricalconnection between the string of series connected resistors 20 and thestring of series connected resistors 22 to thereby form the seriesconnected dummy load line 19.

The top end 66 (FIG. 1) of each vertical tube 24 is connected through aconduit 68 to a steam condenser 70, thereby providing fluidcommunication between each tube and the condenser. For the sake ofexpediency, FIG. 1 only shows one tube connected to tank 34 andcondenser 70, however, in practice all of the tubes are similarlyconnected, although, if desired, each tube may have a separate tank andcondenser for individual control purposes.

In operation, prior to actuation of the transmitter, valve 36 is openedand water from main supply water tank 34 flows into each vertical tube24 to a level above resistors 20. Because the water supply flow isgravity controlled, the water level in the main supply water tank willbe at the same level as the water level in the tubes. The water entersthe tubes through conduits 32 covering glass sleeves 38 and the spacebetween the sleeves and resistors. Thus, a relatively small portion ofthe total amount of water within each vertical tube is partiallyseparated from the main body of water by the sleeve. This allows thatportion of the water to reach the boiling point before the bulk of theliquid within the tube. As the temperature of the load increases, theportion of water within the sleeve is heated and converted to steam. Thesteam, since it is less dense than water, rises rapidly in the spacebetween the resistor and the sleeve, and passes through top 66 of thetube and condenser conduit 68 to steam condenser 70, which converts thesteam into water. The hot water within the space adjacent the resistoralso rises upwardly but at a slower pace than the steam. The result is aconvection flow in the tube, with hot water and steam passing throughthe top, and cooler water coming in at the bottom.

The steam produced adjacent the resistor expands outwardly but can onlygo as far as the glass sleeve. Thus, the pockets of expanding vapor andsteam strike the glass sleeve and rebound toward the resistor. Thisaction produces a high degree of fluid turbulence about the resistor,thereby producing a rapid and efiicient transfer of heat from theresistor to the surrounding medium.

Thus, an eflicient system has been provided for the rapid transfer ofheat from elements such as resistors which generate great quantities ofheat. By providing a sleeve adjacent the resistor, the heat is localizedwithin the tube between the resistor and the sleeve. This enables rapidheating of the portion of the water between the resistor and sleeve,thereby quickly converting the water into steam and providing a morerapid flow of fluid past the resistor for more efficient heatdissipation. The system herein disclosed also enables heater elementswhich supply relatively little heat, to increase the flow of fluid pastthe resistor element, by producing steam in a localized sectionresulting in more efiicient heat dissipation.

While a specific embodiment of this invention has been shown anddescribed in detail to illustrate the application of the inventiveprinciples, it should be understood that the invention may be embodiedotherwise without departing from such principles, and should not belimited except as defined in the following claims.

What is claimed is:

1. A heat transfer system, comprising means for radiating heat, avertically extending sleeve open at both ends spaced from and encirclingsaid heat radiating means, a container spaced from and encompassing saidheat radiating means and sleeve, means for supplying liquid to saidcontainer, said sleeve and said heat radiating means defining a spacetherebetween in liquid connection at the upper and lower ends of saidsleeve with said container, whereby heat radiated from said heatradiating means changes liquid, supplied to said space into gas, thuscreating a fluid flow past said heater means.

2. A system for dissipating heat produced by a dummy load for anelectrical transmitter, comprising a two wire transmission lineconnected across the output of an electrical energy transmitter, aplurality of resistive elements connected in series by said transmissionline, means for enclosing said resistive elements, said enclosing meansincluding vertical outer tubes having steam exits at the top portionsthereof and liquid intakes at the bottom portions thereof, each of saidvertical tubes including therein a concentrically mounted sleeve, saidsleeve having openings at the bottom and top thereof, communicating withthe corresponding one of said outer tubes, one of said resistiveelements being positioned within each of the sleeves whereby the heatwhich radiates from said resistive elements heats the liquid supplied tothe enclosing means converting the liquid adjacent the resistiveelements to steam to initiate a rapid and efficient flow of fluid pastsaid resistive elements.

3. A heat transfer system for a dummy load utilized with an electricalenergy transmitter, comprising a plurality of resistive elements, aplurality of vertical sleeves each open at both ends and surrounding andspaced from a respective one of said resistive elements, a plurality oftubular members each enclosing a respective one of said resistiveelements and the corresponding sleeve, means supplying liquid to each ofsaid tubular members to a level above the tops of said sleeves, andmeans allowing the escape of vapor from each of said tubular members,whereby the heat from said resistive elements changes some of the liquidsupplied to each of said tubular members into vapor and produces a fluidflow that transfers heat from said resistive elements.

4. A heat transfer system according to claim 3, wherein each of saidtubular members includes an upright tube having a pair of transmissionline ports.

5. A heat transfer system according to claim 3, wherein said liquidsupplying means includes a liquid supply tank and conduits providingliquid communication between said tank and tubular members, and saidvapor escape means includes a steam condenser and steam condenserconduits providing fluid communications between the top of said tubularmembers and said steam condenser.

6. A heat transfer system comprising an electrical energy transmitter, adummy load connected across the output of said transmitter, said dummyload including a plurality of resistive elements, a transmission line,and means connecting the resistive elements to the transmission line,said connecting means including a plurality of conductive strapsconnected to each end of each resistive element, a connecting elbowproviding an electrical connection between the straps at each end ofeach resistive element and the transmission line, an open endedcylindrical glass sleeve spaced from and encompassing each of saidresistive elements, a plurality of tabs connected to each end of eachresistive element for supporting the corresponding glass sleeve in avertical position, a plurality of cylindrical glass tubes, each of saidglass tubes enclosing One of said glass sleeves and the associatedresistive element and connecting straps and elbows, a water supply tank,a conduit and conduit control valve provid ing liquid communicationbetween said water supply tank and said glass tube through an opening inthe bottom of the tube, a steam condenser, a conduit providing fluidcommunication between said steam condenser and said tubes throughopenings in the tops of said tubes, a pair of integrally formedextensions projecting outwardly perpendicular to each tube near thebottom and top thereof, said transmission line extending through each ofsaid extensions to connect to the corresponding elbows, whereby theactuation of the transmitter sends electrical energy through the dummyload heating the resistive elements and converting some of the waterwithin the space between the resistive elements and the glass sleevesinto vapor, to dissipate heat generated by said resistive elements.

References Cited by the Examiner UNITED STATES PATENTS 7/1959 Frederico33322 5/1960 Beurtheret 317

1. A HEAT TRANSFER SYSTEM, COMPRISING MEANS FOR RADIATING HEAT, AVERTICALLY EXTENDING SLEEVE OPEN AT BOTH ENDS SPACED FROM AND ENCIRCLINGSAID HEAT RADIATING MEANS, A CONTAINER SPACED FROM AND ENCOMPASSING SAIDHEAT RADIATING MEANS AND SLEEVE, MEANS FOR SUPPLYING LIQUID TO SAIDCONTAINER, SAID SLEEVE AND SAID HEAT RADIATING MEANS DEFINING A SPACETHEREBETWEEN IN LIQUID CONNECTION AT THE UPPER AND LOWER ENDS OF SAIDSLEEVE WITH SAID CONTAINER, WHEREBY HEAT RADIATED FROM SAID HEATRADIATING MEANS CHANGES LIQUID, SUPPLIED TO SAID SPACE INTO GAS, THUSCREATING A FLUID FLOW PAST SAID HEATER MEANS.